Chemical disinfection in healthcare settings: critical aspects for the development of global strategies

Chemical disinfection is an indispensable means of preventing infection. This holds true for healthcare settings, but also for all other settings where transmission of pathogens poses a potential health risk to humans and/or animals. Research on how to ensure effectiveness of disinfectants and the process of disinfection, as well as on when, how and where to implement disinfection precautions is an ongoing challenge requiring an interdisciplinary team effort. The valuable resources of active substances used for disinfection must be used wisely and their interaction with the target organisms and the environment should be evaluated and monitored closely, if we are to reliable reap the benefits of disinfection in future generations. In view of the global threat of communicable diseases and emerging and re-emerging pathogens and multidrug-resistant pathogens, the relevance of chemical disinfection is continually increasing. Although this consensus paper pinpoints crucial aspects for strategies of chemical disinfection in terms of the properties of disinfectant agents and disinfection practices in a particularly vulnerable group and setting, i.e., patients in healthcare settings, it takes a comprehensive, holistic approach to do justice to the complexity of the topic of disinfection.

Disinfectants are antimicrobial agents that are applied to the surface of non-living objects to destroy microorganisms that are living on the objects (retrieved from Infection Control Glossary, Division of Oral Health, U.S. Centers for Disease Control; 2016).

WHO Guideline Hand Hygiene (2009) [35]
Hand disinfection is extensively used as a term in some parts of the world and can refer to antiseptic handwash, antiseptic handrubbing, hand antisepsis/decontamination/degerming, handwashing with an antimicrobial soap and water, hygienic hand antisepsis or hygienic handrub.
Since disinfection normally refers to the decontamination of inanimate surfaces and objects, this term is not used in these Guidelines. ( Disinfection is a process to reduce the number of viable microorganisms to a less harmful level. This process may not inactivate bacterial spores, prions and some viruses. (Glossary, page 10)

Levels of decontamination, disinfection:
The destruction or removal of microorganisms at a level that is not harmful to health and safe to handle. This process does not necessarily include the destruction of bacterial spores (Table 1, page 22).
Disinfectant is a chemical agent that is capable of killing most pathogenic microorganisms under defined conditions, but not necessarily spores. It is a substance that is recommended for application to inanimate surfaces to kill a range of microorganisms. The equivalent agent, which kills microorganisms present on skin and mucous membrane, is called an antiseptic (Glossary, page 10).
Types of commonly-used chemical disinfectants described by active substance ( Disinfection: reduction of the number of viable microorganisms on a product to a level previously specified as appropriate for its intended further handling or use.
Chemical disinfection: achieved by the action of one or more chemicals, the primary purpose of which is to be microbicidal.

EU Regulation No. 528/2012 (Biocide Regulation) [3]
(Disinfection: not specifically defined) (Disinfectant: not specifically defined) Biocidal product means:  any substance or mixture, in the form in which it is supplied to the user, consisting of, containing or generating one or more active substances, with the intention of destroying, deterring, rendering harmless, preventing the action of, or otherwise exerting a controlling effect on, any harmful organism by any means other than mere physical or mechanical action;  any substance or mixture, generated from substances or mixtures which do not themselves fall under the first indent, to be used with the intention of destroying, deterring, rendering harmless, preventing the action of, or otherwise exerting a controlling effect on, any harmful organism by any means other than mere physical or mechanical action.
A treated product that has a primary biocidal function shall be considered a biocidal product (Article 3, Definitions (a), L 167/9). "Active substance" means a substance or a micro-organism that has an action on or against harmful organisms; (Article 3, Definitions (c), L 167/10) Skin disinfection within PT1: Skin disinfection is the reduction of the number of micro-organisms on skin, achieved by the irreversible action of a product, to a level judged to be appropriate for a defined purpose.
PT2, 3, 4: disinfection is the reduction of the number of micro-organisms in or on an inanimate matrix -achieved by the irreversible action of a product, to a level judged to be appropriate for a defined purpose.
A disinfectant is a product that reduces the number of micro-organisms (fungi, yeasts, viruses, algae, bacteria or spores) in or on an inanimate matrixachieved by the irreversible action of a product, to a level judged to be appropriate for a defined purpose.

Antisepsis:
application of an antiseptic on living tissues causing an action on the structure or metabolism of microorganisms to a level judged to be appropriate to prevent and/or limit and/or treat an infection of those tissues.

Chemical disinfection:
reduction of the number of microorganisms in or on an inanimate matrix, achieved by the irreversible action of a product on their structure or metabolism, to a level judged to be appropriate for a defined purpose. (disinfection: not specifically defined)

Antimicrobial agent:
Defined in section C.01A.001 of the Food and Drug Regulations as: a drug that is capable of destroying pathogenic micro-organisms and that is labelled as being for use in the disinfection of environmental surfaces or medical devices, as defined by the Medical Devices Regulations, that (a) are not invasive devices as defined in those Regulations; and (b) that are intended to come into contact with intact skin only.

Disinfectant:
A substance, or mixture of substances, capable of destroying or irreversibly inactivating pathogenic (disease-causing) and potentially pathogenic (opportunistic) microorganisms, but not necessarily bacterial spores, present on environmental surfaces and inanimate objects due to the antimicrobial action of the active ingredient(s).

Disinfectant-sanitizer:
A chemical product represented for use as a sanitizer on hard non-porous environmental surfaces and inanimate objects which is also represented for use as a hard surface disinfectant.
Categories of disinfectants for use on non-critical medical devices and hard nonporous environmental surfaces and inanimate objects by premise: in food processing  and/or barn premises.